The Quantitative Morphology Core (QMC), directed by Dr. Patrick Hof, provides expertise with quantitative neuroanatomical methods and image analysis, as well as help in study design to the Center's investigators. An important feature of the QMC is its capability to cross levels of morphological resolution, from macroscopic features to subcellular characteristics, to provide a comprehensive understanding of neurochemical morphology, not only in the context of functional circuits, but also in relation to the behavioral and electrophysiological paradigms employed by the Center's investigators. The QMC is equipped with two computer-assisted photomicroscopes, one confocal laser scanning microscope and has full access to an electron microscope facility. Quantitative morphology is performed principally using NeuroZoom, a software application designed for full-scale mapping, cell reconstruction, image analysis and stereology. In view of the very high level of interaction in terms of quantitative anatomic analyses among the different members of the Center, a key role of the QMC is to generate a uniform approach to quantitative neuroanatomy in order to ensure a high level of consistency in analysis, statistics, and interpretation of the morphologic data. Specifically, the QMC will participate in collaborative studies of glucocorticoid and glutamate receptor localization in projection neurons in the medial prefrontal cortex and amygdala as well as in intra-amygdala circuits (with Projects 1 and 3), stereologic analysis of neuron numbers and structure volumes of select subfields in the hippocampus (with Project 4), and quantitative cellular reconstructions of physiologically characterized and dye-filled neurons to assess the degree of stress-induced dendritic atrophy in all three brain regions (with Projects 1 and 3). In addition, the QMC will continue to develop new methods to optimize sampling on confocal images and to permit stereology on electron microscopy materials. It will collaborate with Projects 2 and 4 to provide neuroanatomical expertise to interpret MRI scans from experimental animals and human subjects, particularly with respect to delineation of regional boundaries in the hippocampal formation, and will assist with statistical analyses of regional volumes estimates calculated from the MRI.